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CN-115749572-B - Extension ladder

CN115749572BCN 115749572 BCN115749572 BCN 115749572BCN-115749572-B

Abstract

The invention relates to an extension ladder, which comprises an extension ladder body, wherein the front end and the rear end of a cross rod at the uppermost end of the extension ladder body penetrate through a ladder tube where the extension ladder body is positioned and are hinged with a protective cover, the protective cover consists of three frames, each frame comprises two side plates and a movable plate movably connected between the two side plates, corresponding positioning holes are formed in the two side plates, a fixed shaft is arranged between the two side plates, a movable plate close to the outer edges of the two side plates is arranged between the two side plates, the movable plate comprises an extension rod and two blades, the upper ends of the upper blades in the two blades are rotatably connected with the fixed shaft, and the hinged end parts of the two blades and the lower ends of the lower blades in the two blades are movably connected with one group of positioning holes on the two side plates through the extension rod. The invention relates to an extension ladder with a protection function and convenient maintenance operation, which is particularly suitable for maintenance and overhaul work of an optical cable in mountain areas.

Inventors

  • WANG KE
  • DENG JIANJUN
  • LIU ZILI
  • SONG LIQIANG
  • LI FAN

Assignees

  • 中国通信建设集团有限公司河南省通信服务分公司

Dates

Publication Date
20260508
Application Date
20221130

Claims (8)

  1. 1. The telescopic ladder comprises a telescopic ladder body, wherein the telescopic ladder body comprises a plurality of groups of ladder pipes (1), the upper ladder pipes (1) are contracted in the lower ladder pipes (1) in two adjacent groups of ladder pipes (1), and a cross rod (2) is arranged between each group of ladder pipes (1), and the telescopic ladder is characterized in that the front end and the rear end of the cross rod (2) at the uppermost end of the telescopic ladder body penetrate through the ladder pipes (1) at the front side and the rear side, and a protective cover is hinged between the two ends; The protective cover is composed of three frames (3), each frame (3) comprises two side plates (4) and a movable plate (5) movably connected between the two side plates (4), a fixed shaft (8) is arranged between the upper ends of the two side plates (4), a movable plate (5) close to the outer edges of the two side plates (4) is arranged between the two side plates (4), the movable plate (5) comprises a telescopic rod (10) and two hinged blades (9), the upper ends of the blades (9) positioned above are rotatably connected with the fixed shaft (8), the hinged parts of the two blades (9) and the lower ends of the blades (9) positioned below Fang Sheban are both hinged with the telescopic rod (10), and the two ends of the telescopic rod (10) are movably connected with the two side plates (4); The side plates (4) on the same side of the three frames (3) are on the same vertical plane, the frame (3) positioned at the lowest part is provided with a rolling shaft (11) which is close to the outer edge of the frame (3) and the lower end of the frame (3), and the peripheral wall of the rolling shaft (11) is in rolling contact with the ladder tube (1); The two side plates (4) of each frame (3) are in front-back symmetry, the two side plates (4) are fan-shaped plate bodies, the two side plates (4) are rotationally connected with two ends of the uppermost cross rod (2) through a connecting ring (6) at the center of a circle, positioning holes (7) corresponding to each other in front-back are formed in the two side plates (4) of each frame (3), each positioning hole (7) comprises a first positioning hole (19), a second positioning hole (20) and a third positioning hole (21), the first positioning hole (19) is located between the fixed shaft (8) and the outer edge of the side plate (4), the second positioning hole (20) is close to the middle of the outer edge of the side plate (4), and the third positioning hole (21) is close to the middle of the lower edge of the side plate (4); The two ends of the telescopic rods (10) positioned above in each frame (3) are movably connected with the two side plates (4) through second positioning holes (20), the two ends of the telescopic rods (10) positioned below are movably connected with the two side plates (4) through third positioning holes (21), or the two ends of the telescopic rods (10) positioned above in the two telescopic rods (10) in each frame (3) are movably connected with the two side plates (4) through second positioning holes (20), and the two ends of the telescopic rods (10) positioned below are movably connected with the two side plates (4) through third positioning holes (21) in the two telescopic rods (10) positioned below in the other frames except the lowest frame.
  2. 2. The telescopic ladder according to claim 1, wherein the blades (9) are rectangular plates, through grooves (12) which are concave towards the blades (9) and have outward openings are formed in the middle parts of two long sides of the blades (9), hinge tubes (13) are arranged on the blades (9) on the front side and the rear side of the through grooves (12), a telescopic rod (10) is arranged in the hinge tubes (13) at the hinged positions of the two blades (9) in a penetrating mode and in the hinge tubes (13) at the lower ends of the lower Fang Sheban (9) of the two blades (9), and the hinge tubes (13) at the upper ends of the blades (9) above in the two blades (9) are sleeved outside the fixed shaft (8).
  3. 3. The telescopic ladder according to claim 1, wherein a plurality of groups of adjusting holes (22) corresponding to each other are formed in two side plates (4) of the frame (3) located at the lowest position in the three frames (3), each of the plurality of groups of adjusting holes (22) is arranged on a circle with a fixed shaft (8) of the side plate (4) located at the center and a center distance between a second positioning hole (20) of the side plate (4) located at the center and the fixed shaft (8) being a radius, two ends of the telescopic rod (10) located at the highest position in the frame (3) located at the lowest position are movably connected with the two side plates (4) located at the lowest position through any one group of adjusting holes (22), and when two ends of the telescopic rod (10) located at the highest position in the frame (3) are movably connected with the two side plates (4) located at any one group of adjusting holes (22), two ends of the telescopic rod (10) located at the lowest position in the frame (3) are in contact with the side plate (4) located at the lowest position.
  4. 4. A telescopic ladder according to claim 3, characterized in that the two ends of the telescopic rod (10) located above in the lowermost frame (3) are movably connected with the two side plates (4) via one group of adjusting holes (22), and when the center distance between the group of adjusting holes (22) and the second positioning holes (20) on the side plates (4) is equal to the center distance between the two telescopic rods (10) on the movable plate (5), the two ends of the telescopic rod (10) located below in the lowermost frame (3) are movably connected with the two side plates (4) via the second positioning holes (20).
  5. 5. An extension ladder according to claim 1, characterized in that the extension rod (10) comprises a sleeve (14), two sliding rods (15) and a compression spring (18), the sleeve (14) is arranged in the hinge tube (13) in a penetrating manner and is in sliding contact with the hinge tube (13), penetrating holes (16) corresponding to through grooves (12) in the blade plate (9) are formed in the middle of the peripheral wall of the sleeve (14), sliding rods (15) in sliding contact with the inner peripheral wall of the sleeve (14) are arranged in the front portion and the rear portion of the sleeve (14), deflector rods (17) extending out of the penetrating holes (16) are arranged on the peripheral walls of the opposite ends of the two sliding rods (15), the other ends of the two sliding rods (15) extend out of the sleeve (14), and the compression spring (18) located in the sleeve (14) is arranged between the opposite ends of the two sliding rods (15) and corresponds to the penetrating holes (16).
  6. 6. The telescopic ladder according to claim 1, characterized in that the upper ends of two ladder pipes (1) of a group of ladder pipes (1) at the uppermost end of the telescopic ladder body are connected with a hook (23) with free ends far away from a protective cover, the hook (23) is an n-shaped rod body formed by sequentially connecting two straight rods and an arc rod, corresponding through holes (24) are formed in the two straight rods of the hook (23), a clamping plate (25) is hinged in the through hole (24) of one straight rod, the clamping plate (25) is a fan-shaped plate body, the circle center of the clamping plate (25) is hinged with the upper end of the through hole (24), a threaded hole penetrating through the free end of the hook (23) and communicating with the through hole (24) is formed in the free end of the hook (23), a bolt (26) is connected in the threaded hole, and the bolt (26) penetrates through the threaded hole to tightly prop against the peripheral wall of the clamping plate (25).
  7. 7. The telescopic ladder according to claim 6, wherein the peripheral wall of the clamping plate (25) is provided with saw teeth (27) inclined towards the free end of the hook (23), the end face where the connecting line between the upper end of the peripheral wall of the clamping plate (25) and the circle center is located is the working face of the clamping plate (25), and the working face of the clamping plate (25) is provided with a semicircular notch which is concave downwards and is upward in opening.
  8. 8. The telescopic ladder according to claim 1, characterized in that the lower ends of two ladder pipes (1) of a group of ladder pipes (1) at the lowest end of the telescopic ladder body are connected with cones (28) with downward tips, support rods (29) on the same side as the free ends of hooks (23) are connected to the two ladder pipes (1) of the group of ladder pipes (1) at the lowest end of the telescopic ladder body, and the right ends of the support rods (29) are connected with the ladder pipes (1) and the left ends are rotatably connected with rollers (30).

Description

Extension ladder Technical Field The invention relates to the technical field of optical cable maintenance tools, in particular to an extension ladder. Background The aerial optical cable is an optical cable hung on the electric pole in a hanging mode, and the aerial optical cable laying mode can utilize an original aerial open-line pole, so that construction cost is saved, and construction period is shortened. The aerial optical cable is hung on the electric pole, is required to be suitable for various natural environments, is generally used for long-distance secondary or less lines, and is suitable for special network optical cable lines or certain local special sections. The aerial optical cable is usually completed by adopting an overhaul vehicle during overhaul, but is unsuitable for use in mountain forest areas with inconvenient traffic, the common ladder is large in weight and size and is not suitable for being carried and used in mountain forest areas, the telescopic ladder is light in weight and small in storage size, is suitable for being carried in mountain forest areas and is used for aloft work, the telescopic ladder disclosed in the apparent patent with the application number 202230124627.3 is commonly used for maintaining the optical cable at present, the structure of the telescopic ladder is similar to that of the telescopic ladder with the anti-pinch structure with the application number 201820421159.4, the telescopic ladder comprises ladder pipes, transverse rods are arranged between the ladder pipes, stop blocks are arranged on the lower surfaces of the transverse rods, and the transverse rods are connected with the ladder pipes through locking structures. The existing telescopic ladder can only lean on the steel strand of the optical cable, and when in use, maintenance personnel need to stand on the telescopic ladder for maintenance, so that the operation is inconvenient, no protection exists, and accidents are easy to occur. Disclosure of Invention In order to solve the problems in the prior art, the invention provides an extension ladder, and aims to provide an extension ladder with a protection function and convenient maintenance operation. In order to achieve the above object, the technical scheme of the present invention is as follows: The telescopic ladder comprises a telescopic ladder body, wherein the telescopic ladder body comprises a plurality of groups of ladder pipes, the ladder pipes at the upper part are contracted in the ladder pipes at the lower part, cross rods are arranged between each group of ladder pipes, the front end and the rear end of the cross rod at the uppermost end of the telescopic ladder body penetrate through the ladder pipes at the front side and the rear side, and a protective cover is hinged between the two ends; The protective cover consists of three frames, each frame comprises two side plates and a movable plate movably connected between the two side plates, a fixed shaft is arranged between the upper ends of the two side plates, a movable plate close to the outer edges of the two side plates is arranged between the two side plates, the movable plate comprises a telescopic rod and two hinged leaf plates, the upper ends of the leaf plates positioned above the two leaf plates are rotatably connected with the fixed shaft, the hinged parts of the two leaf plates and the lower ends of the leaf plates positioned below the two leaf plates are both hinged with the telescopic rod, and the two ends of the telescopic rod are movably connected with the two side plates; The side plates on the same side of the three frames are arranged on the same vertical surface, and the frame positioned at the lowest side is provided with a rolling shaft close to the outer edge of the frame and the lower end of the frame, and the outer peripheral wall of the rolling shaft is in rolling contact with the ladder tube. Further, the blades are rectangular plates, through grooves which are sunken towards the blades and are outward in opening are formed in the middle of two long sides of each blade, hinge shaft pipes are arranged on the blades on the front side and the rear side of each through groove, a telescopic rod is arranged in the hinge shaft pipe of the hinged position of the two blades and in the hinge shaft pipe of the lower end of the lower blade in a penetrating manner in the hinge shaft pipes of the two blades, and the hinge shaft pipe of the upper blade in the two blades is sleeved outside the fixed shaft. Further, every two curb plates of frame bilateral symmetry, two curb plates are the sector plate body, and two curb plates all rotate the horizontal pole both ends of connecting the uppermost through the go-between of centre of a circle department, all are equipped with corresponding locating hole around on two curb plates of every frame, the locating hole includes first locating hole, second locating hole and third locating hole, first locating hole is located between